1. Field of the Invention
The present invention relates to an electronic musical instrument that can simulate the performance of an ensemble by generating a plurality of tone colors in response to a key operation.
2. Prior Art
Electronic musical instruments that can synthesize musical tones such as piano tones by using digital LSI (Large-Scale-Integration) and other components have been developed. These types of conventional musical instruments generally have a depressed-key-detecting circuit and a musical-tone-signal-generating circuit. The depressed-key-detecting circuit scans a keyboard to detect a depressed key, and generates a keycode representing the tone pitch associated with the depressed key. The musical-tone-signal-generating circuit generates musical-tone signals corresponding to the tone pitch and having a tone color preset by a tone-color-setting switch. The musical-tone signals thus generated are amplified by an amplifier, and musical tones corresponding to the musical-tone signals are produced from a speaker.
In addition to the instruments described above, some instruments which can simulate the performance of an ensemble have been developed. These instruments have musical-tone-signal-generating circuits that can generate a plurality of musical-tone signals of different tone colors, such as those of a piano and a violin, in response to a key operation, thus generating a combination of musical tones of different tone colors.
There are two types of these conventional instruments:
(1) In the first type of conventional instrument, the combination of ensemble tones, such as piano and violin, or organ and flute, is determined and prestored in ROM in the fabrication process. Hence, a performer can merely select one of these combinations before or during performance. (2) In the second type of conventional instrument, a plurality of musical-tone-signal-generating channels are provided, and each tone color is assigned to one of the musical-tone-signal-generating channels.
These instruments, however, present the following problems:
In the first type of instrument above, a combination other than the combinations set in the fabrication process cannot be selected, thus restricting the freedom of choice of the combinations of ensemble tone colors.
In the second type of instrument above, a tedious operation is required to assign combinations of tone colors to the channels, making it difficult to change combinations during performance.